Fitting 1973-87 power windows is a one-door-at-a-time job, and the glass runs in the factory channel when you are done. Our kit for 1973-87 Squarebody doors replaces the hand crank regulator in a Squarebody door with an electric regulator, motor and switches. The mounting position changed in 1977, so the two diagrams below cover the early and late doors. First, identify your door. Then follow the diagram, and use the wiring notes further down before the door panel goes back on.
1973-87 power windows kit mounting
1973-1976 GMC Chevy Truck Left Side:
1977-1987 GMC Chevy Truck Left Side:
Tools you will need
- Door panel removal tool and basic hand tools
- Drill with a 5/32″ bit and a 10-32 tap for the harness clip
- 7/8″ hole saw or step bit for the kick panel grommet
- Wire strippers, crimps and a test light or multimeter
Wiring and switch tips
- First, disconnect the battery before any wire goes into the door.
- Bench test each motor on the truck battery before the regulator goes in. It is far easier to swap a motor on the bench than inside a door.
- Route the harness through the hinge side with a grommet, and leave enough slack for the door to open fully without pulling on the wire.
- Fuse the circuit at the source. A 20 amp fuse covers a pair of power window motors on most kits.
- Finally, test the switches before the door panel goes back on. If a window runs the wrong way, swap the two motor wires at the switch.
1973-87 power windows fitment notes
Every one of these doors has a different history, so expect to trim a bracket or move a hole once in a while. Also, run the glass up and down by hand before the motor is connected, because a stiff channel will stall a motor that is otherwise fine. New felt run channels make a bigger difference than most people expect. The rest of the door hardware for the same cab is in our 73-87 Squarebody truck parts collection.
Mounting differs between the early and late trucks, so check yours before ordering (if the paperwork is gone, our VIN decoder will give you the year) — we list parts by year for the 1978 Chevy and 1985 Chevy trucks, or browse the full 73-87 Squarebody truck parts collection.
For any questions or concerns with your install, don’t hesitate to email us at info@lsfab.com
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